Radar and electronic warfare (EW) systems require antenna elements to interface the system with the atmosphere. The antenna elements should present as low a VSWR (voltage standing wave ratio) as possible to the driving electronics for efficient transfer of power between the system and the atmosphere. The ability to tune an antenna element for the correct impedance at a given frequency greatly enhances the efficiency and bandwidth of the system. Tuning may be accomplished either manually or automatically, which represents a significant enhancement to typical radar or EW systems.
As one can ascertain, many different radar antennas exist, which vary both in size and function. However, the basic function of a radar antenna is to direct through the atmosphere the radiated power and receiver sensitivity to the azimuth and elevation coordinates of a target. It is generally desirable in radar systems to substantially reduce the VSWR and to provide an efficient way of tuning a radar element so that one can correct the impedance of the radar at given frequencies. This can significantly enhance the efficiency and bandwidth of the operational system. Existing solutions use a fixed dielectric constant material and trade off bandwidth for VSWR. Alternative mechanisms for providing a reconfigurable antenna are desired.